Pick whichever you want, and post here the moment you decide, so we dont end up duplicating If I get some time, I'll take a couple and plough thru them. It would be nice to wrap it all into a little PDF article with pictures etc - like an extract from a pretend UMSF Journal or some such publication - and if I'm fortunate enough to do something like this again, I could do it the same way

So - I've 'chopped' it up into about a dozen virtual sections each somewhere between 3 and 6 mins long, and if volunteers want to pick one, post here and then post the finished text when done and I'll string it all together as a PDF when it's done

BEGIN PART ONEDoug: This is Doug Ellison of unmannedspaceflight.com. The weekend of September 3 saw a weekend-long planetary conference of the British Astronomical Association to coincide with the 2005 DPS conference in Cambridge, England. After an excellent talk on recent scientific findings by the Mars Exploration Rovers, Steve Squyres took time to answer questions submitted by forum members in the gardens of the famous Cavendish laboratory.But with recent tragic events in the southern USA, my first question was of course about the aftermath of Hurricane Katrina.

Steve: It's been very tough to watch on TV over here, being so far away. Have friends -- used to have family in New Orleans but they've left -- have friends in New Orleans, I've heard from all of them. Everybody's OK, but still it's just a horrific thing to watch on television.

Doug: On a very slightly lighter note, MER came out of what seems like failure after nightmare after turndown --

Steve: We had our share of crises and disappointments.

Doug: At some point after kind of, proposal after proposal, did you think this isn't worth my time, I'm going to give up? Did you come close?

Steve: I was -- there were times when it was hard to keep going. I never came close to quitting. I will be very honest with you, and tell you that there was a point where a primary driver, I won't say the primary driver, but where a primary driver was simply fear. Was simply the fear that if I quit now, the last decade of my career would have been mostly wasted, and I just didn't want to see that happen. But I think, fundamentally I always knew, I knew from the very start that if we could get this to the launchpad, if we could get it to Mars, and if we could make it work it was going to be something really great. And just that knowledge was enough to keep us going through some fairly difficult times.

Doug: You came pretty close with the 2001 lander.

Steve: I was six weeks away from delivering a calibrated payload to the loading dock at Lockheed Martin. Yeah, we came real close.

Doug: Now, if you'd have got through that six weeks, if HQ had gone, let's fly the 2001 lander, and you'd have gone to Meridiani with Marie Curie --

Steve: Oh, God. Oh, I've had nightmares about that. Because that lander's not going to come to a stop in a crater.

Doug: No.

Steve: That just comes down where it comes down, and you just ask yourself what fraction of Meridiani Planum is craters. Okay. We would have landed out on those plains. We would have had the blueberries. We would have figured out that they were probably rich in hematite. We would have had some basaltic sand. And we would have had pictures of a whole bunch of nothing. And that's what we would have had.

Doug: You think Marie Curie could have stood in and managed anything?

Steve: Marie Curie could go 50m away from the lander maybe, but after that you basically lose control of the thing. I mean, maybe, you know, you could just send her trundling off into the distance -- I don't know what the range on the telecom system on that thing actually is. But all it's got is some really rather poor cameras and an APXS. You can't do mineralogy with it, no microscopic imaging capability on it. No, we would have been confused. We never would have figured it out.END PART ONE

I apologize for anyone who had his or her heart set on this section, but I got a little carried away:BEGIN PART TWODoug: Now, we're going to crack on with the rovers.

Steve: Yeah.

Doug: The talk you just gave to the BAA kind of answered this question, but we -- everyone knows the story of Eagle Crater. You got the concretions, you got crossbedding, you got the salts --

Steve: We got lucky.

Doug: Yeah, very. But kind of lost in, kind of media interest waning away -- how much did Endurance Crater add to that story?

Steve: Oh, tremendously. Tremendously. Because when we had Eagle, all we had was the upper, you know, half-meter of stratigraphy. We couldn't put it into any proper context. We didn't know how much things varied laterally, we didn't know how much things varied vertically. By going laterally 800m we began to get a sense that this stuff is continuous over large distances. And then by going vertically, something like 10m, we actually saw quite a variety. What we found was that although the stuff at the top of the stack was in fact deposited in liquid water, because you see the ripples, most of the stuff that you see in the wall of Endurance Crater was deposited by wind. Certainly the lower portion of the section, and probably the whole middle section, is dunes and sand sheets.A good analogy is a place in the southwestern United States called White Sands.

Doug: New Mexico.

Steve: Yeah, New Mexico. And what happens in White Sands is there are these playas, okay, where liquid water comes to the surface and evaporates away, and it leaves salt deposits behind, or sulfates. And they're much cleaner sulfates than the ones at Meridiani, but they're sulfate salts. And then what happens is those playas serve as the source for this sulfate sand that then blows around and builds the beautiful white sand dunes. And so what you got is mostly a dune deposit of salty dune sand with water in the low spots between the dunes. And that's probably the situation that we had at Meridiani Planum. We could have put none of that story together if we'd had only what we had over at Eagle. So Endurance was enormously valuable.

Doug: One rock that stands out in there that almost seems to be completely out of context is Wopmay.

Steve: I don't think Wopmay's out of context. Wopmay probably rolled down the hill to its current location. The interesting thing about Wopmay is that it's got a very weird surface texture. When you look at Wopmay carefully, what you see is that it's laced by this pattern of polygonal fractures that seemed very weird and very exotic at the time. The first place that we saw polygonal fractures was Escher. I don't know if you remember that one. But it was one that was way down at the bottom of the crater.

Doug: Yeah...

Steve: That totally freaked us out when we first saw that. Spent a lot of time on that one. Then we drove over to Wopmay and realized that it's got a pattern of polygonal fractures, and then what we've seen since then is that these polygonal fractures are all over the place. If you look at where Opportunity is right now, okay, that outcrop called Ice Cream, the one where Lemon, Lime and Strawberry are. All of those have this wonderful polygonal fracture pattern. Wopmay, the polygonal fracturing is on the surface of the boulder instead of this flat plateaued surface. But it's the same stuff. And it's weathered, it's eroded to this kind of a lumpy shape. We think that the polygonal fracturing -- I mean, when you see polygonal fracturing like that, it's the consequence of some kind of volume change, something is shrinking a little bit. These salts, the calcium sulfates, the magnesium sulfates, can contain a lot of water. It's water of hydration, it's not liquid water, it's H2O that is bound up in the crystalline structure, the crystal lattice of the salts. And then if there's a dehydration process, where the relative humidity in the outside environment drops a little bit, the salts will tend to dehydrate, as they lose their water they contract. They shrink. And so we think this polygonal fracturing out on the plains, at Escher, in Wopmay may be a consequence of the slight dehydration of the sulfate salts in the rock.END PART TWO

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